1. Glyoxal emission over East Pacific: A primary biogenic source?
Ruixiong Zhang
04/24/2014
Advisor: Dr. Yuhang Wang

2. Glyoxal (C2H2O2) Smallest di-carbonyl Oxidation of many VOCs
Very small primary sources
Great for constraints of emissions
Substantial underestimate of aromatics in China by a factor of (Liu et al., 2012)
What is glyoxal and why we care about glyoxal

3. Satellite retrieved glyoxal Vertical Column Densities (VCDs)
SCIMACHY larger than GOME-2 over land. China->Aromatics, South Africa, Southeast US, South America->biomass burning related, fire activities. Turn to next page (this really low values are due to water vapor interference). But what is going on these remote ocean regions?
Overpassing time:
GOME-2 9:30 LT
SCIAMACHY 10:30 LT

4. SCIA retrievals. Water vapor interference.

5. Is glyoxal over Pacific due to Acetylene or Glyoxal Primary sources?
Glyoxal sources
Is glyoxal over Pacific due to Acetylene or Glyoxal Primary sources?
(Fu et al., 2008)

6. Comparison between glyoxal and acetylene VCDs
Acetylene doesn’t appear to be the source of glyoxal over oceans
Possible glyoxal primary sources?
(Duflot et al., 2013; Kanakidou et al 1988)

10. May lead to 2.8-5.6 Tg C/year of SOA
2007 Estimated glyoxal emission over Pacific (20-40 Tg/yr)
(Global continential glyoxal emission ~45Tg/yr (Fu et al., 2008))
May lead to Tg C/year of SOA
We may use VCDs temporal pattern to represent that of emissions.
Posteriori emission follows the pattern of VCDs indicating that meteorology variation
is trivial.

11. Why?

12. Glyoxal anomaly versus ENSO (related to biogenic activity)
A possible direct biogenic sources over oceans

13. Conclusions and future work
A very possible glyoxal biogenic primary source in Pacific (20-40 Tg/yr)
Find out why glyoxal VCDs exhibit a bi-peak seansonal cycle

14. Thank you!
Question time!